(a) Field of the Invention:
The present invention relates to a switch for remote-controlling the motions about a vertical axis and horizontal axis of the reflective face of a motor-driven mirror installed on an automobile.
(b) Related Art Statement:
A remote-controlled motor-driven automotive mirror device has in the mirror housing the motors which are adapted to rotate the mirror surface about the vertical and horizontal axes, respectively. The mirror surface of either of the right and left mirrors of the automobile is moved about the vertical axis and horizontal axis by rotating in the forward or reverse direction the motors which correspond to the axial moves, respectively. The forward and reverse rotations of such motors are controlled by means of a control switch provided between the motors and a direct-current power source for energizing the motors, namely, a battery, and a switching circuit to tilt desired one of the mirrors in a desired direction. Such control switch is equipped with a manipulating switch to alternatively rotate the mirror surface about the vertical axis and horizontal axis and a bidirectional changeover switch to select either one of the right and left mirrors of the automobile to be moved, and is located near the driver's seat in the automobile for the driver to operate it by touching it by his or her finger.
For example, a mirror surface tilting device comprising such a control switch as above is disclosed in Japanese Unexamined Utility Model Publication No. 58-40451.
The control switch comprises a push-plate provided as exposed in an opening at the top of a box-shaped casing that is rectangular in the cross-sectional shape, a plurality of stationary contacts formed on a circuit board, and a pair of arc-shaped bridge members provided between the push-plate and circuit board, made of an electrically conductive elastic substance and arranged in parallel for selectively connecting specific ones of the plurality of stationary contacts on the circuit board. The push-plate has on its front surface four pressing positions, U, D, R and L, in correspondence to the upward, downward, rightward and leftward directions in which the mirror surface will be tilted, and has on its back surface four projections touching the circumferential face near both ends of a pair of bridge members, respectively, the pair of bridge members movably supporting the push-plate. When one of the pressing positions of the push-plate is depressed, two of the four projections press in relation to the depressed position both ends of one of the paired bridge members or one end of both of the paired bridge members, respectively, and the bridge member or members concerned are elastically deformed. At that time, the end of the pressed side of bridge member slides in the direction toward the other end of the bridge member to connect specific stationary contacts each other. Thus a switching operation is effected by depressing one of the pressing positions on the push-plate, and a specific motor is thereby rotated to tilt the mirror in the direction corresponding to the depressed position of the push-plate.
A conventional control switch as described above makes a selective connection between stationary, contacts, namely, a switching operation, by letting the projections integrally formed on the back of a push-plate press the circumferential face of one or both of two paired bridge members for thereby elastically deforming the bridge member or members concerned. The switching operation is conducted by the driver depressing the push-plate by his or her finger, and because the push-plate itself acts on the bridge member or members, the switching touch felt by the driver is not light but heavy, posing a problem in operability. There also is a problem that the depressing pressure felt by the driver varies depending on the depressed position of the push-plate. Heavy touch and variable depressing pressure in such mechanical switching give a psychologically uneasy feel to the driver, and unnecessary attention may be concentrated by the driver on the control switch at the time of the switching operation; therefore, a control switch of light touch and uniform depressing pressure is demanded.
Further, since the entirety of the push-plate moves up and down with respect to the outer casing which defines the switch unit, there are clearances between the push-plate and outer casing to let the push-plate move smoothly, and there is an opening in the center of the push-plate through which the upper portion of the knob to manipulate a bidirectional changeover switch is inserted; therefore, it is deemed that dust, beverage and other foreign objects possibly enter through the clearances and opening from outside the control switch unit into the inside of the switch unit in which there are pluralities of stationary contacts and bridge members, adhere to the stationary contacts and the slide contacts of the bridge members in the portions where they touch each other, and hinder the bridge members from smoothly moving and/or cause them to be in poor contact with the stationary contacts.